1. Field of the Invention
The present invention concerns a diode laser device in which diodes are arranged in a plurality of semiconductor arrays disposed parallel to each other and fixed to a heat diffusing substrate in turn connected to a cooling system. The laser diodes are grown epitaxially on semiconductor substrates which are cut into strips to form said laser diode arrays. A diode laser device of this kind is described in, for example:
I.E.E.E Journal of Quantum Electronics, Vol. 28, No. 4, April 1992, pages 952 to 965 "High Power Diode Laser Arrays" and pages 966 to 976 "Modular Microchannel Cooled Heatsinks for High Average Power Laser Diode Arrays; and U.S. Pat. No. 5,128,951. PA1 a heat diffusing substrate made from a material that is a good conductor of heat, in one face of which is formed a system of parallel ribs and grooves, said ribs being identical and equidistant, and PA1 a plurality of semiconductor arrays incorporating said diodes and housed longitudinally in said grooves, PA1 wherein said grooves have an at least approximately triangular cross-section joined to said substrate by one side and each semiconductor array is fixed flat to an oblique flank of one of said ribs. PA1 two semiconductor arrays are disposed in each groove, fixed flat to the facing divergent oblique flanks of said groove, PA1 said semiconductor arrays have the same type of conductivity, PA1 said interruption strips of said metalization film are in vertical alignment with apexes of said ribs, PA1 in each groove, a first conductor electrically connects to each other the two semiconductor arrays, and PA1 second conductors connect, each time, the first conductor of one groove to the part of said metalization film in the adjacent groove. PA1 a single semiconductor array is disposed in each groove so that all said semiconductor arrays of said device are fixed flat to parallel oblique flanks, PA1 said semiconductor arrays have the same type of conductivity, PA1 said interruption strips of said metalization film are in vertical alignment with said bases of said grooves, and PA1 in each groove, a conductor electrically connects said semiconductor array therein to the part of said metalization film covering said oblique flank opposite said oblique flank to which said semiconductor array is fixed. PA1 two semiconductor arrays are disposed in each groove, fixed flat to said divergent oblique flanks delimiting said groove, PA1 said two semiconductor arrays in a groove have opposite types of conductivity and all said semiconductor arrays having one type of conductivity are fixed to parallel oblique flanks, PA1 said interruption strips of said metalization film are in vertical alignment with said bases of said grooves, and PA1 in each groove, a conductor connects to each other said two semiconductor arrays having the opposite conductivity types.
2. Description of the Prior Art
Diode laser devices have many applications, for example pumping solid lasers (see U.S. Pat. No. 4,847,851), fiber optic links, laser treatment of materials, medicine, etc.
The diode laser devices known in themselves at this time and described in the prior art mentioned above are essentially of two types.
In the first type, the semiconductor arrays are welded flat onto one face of the heat diffusing substrate and this face is machined between two adjacent semiconductor arrays to form mirrors to reflect the radiation emitted by the diodes opposite said face. In an implementation of this kind the heat is extracted from said diodes efficiently, with the result that they operate reliably. On the other hand, it is not possible to obtain sufficiently dense and uniform radiation in this way.
In the second type of device known in itself one face of the heat diffusing substrate is provided with a system of parallel ribs and grooves of rectangular cross-section, said grooves forming housings in which said semiconductor arrays are disposed longitudinally on edge. An arrangement of this kind increases the density of the semiconductor arrays on the heat diffusing substrate, but does not provide a high density of radiation because the evacuation of heat is insufficient, given the small surface area of contact. The laser diodes therefore overheat and are quickly destroyed if a high radiation density is required.
An object of the present invention is to remedy these drawbacks by increasing the density and the uniformity of the radiation from a diode laser device. It increases thermal exchange between the arrays and the heat diffusing substrate and the service life of said diodes, simplifies the electrical connections of the semiconductor arrays and enables automated production of said device so that its manufacturing costs are reduced.